Effect of Carbon Nanotubes Addition on the Formability of Al-CNT Composite

Abstract

Being very strong fibers, carbon nanotubes (CNTs) are excellent choice for various metal matrix composites (MMCs). Many researchers have reported amelioration in mechanical and thermal characteristics of the MMCs driven by CNTs addition. However, the effect of multi-walled carbon nanotubes (MWCNTs) addition on the formability of the MMC is relatively less addressed area. In present study, 0.2 wt. % MWCNTs were added in aluminum matrix using induction melting technique and their effect on the various aspect of metal forming characteristics were studied. Two different type of MMC were prepared i.e., re-melting flux (RM) MMC using re-melting flux and multi-functional flux (MF) MMC using multifunctional flux.The experimental results showed that the MF Flux MMC had ultimate tensile strength 65% more than pure aluminum. An analogous behavior was seen in true stress-true strain characteristics along with necking stress and tensile toughness. Contrarily, the hardening factor, strength coefficient, necking strain and strain rate sensitivity values decreased in case of RM Flux MMC and increased for MF Flux MMC as compare to the pure aluminum. This behavior of the materials could be attributed to the process variation used for the incorporation of nanotubes in aluminum matrix.